Xyrem (sodium oxybate)

Reviewed by: HU Medical Review Board | Last reviewed: January 2022 | Last updated: October 2022

Xyrem (sodium oxybate) is one of the only drugs prescribed to treat both the daytime sleepiness and cataplexy of narcolepsy. It is approved for use in people with narcolepsy ages 7 and older.1

How does Xyrem work?

Xyrem is a central nervous system depressant (sedative). It works especially well to control severe cataplexy. Some improvements may be seen in the first few days. However, it can take up to 3 months or longer before it fully helps with symptoms.2

Xyrem comes as a liquid that is mixed with water and taken by mouth on an empty stomach. It is usually taken twice during the night, once at bedtime, and again 2 ½ to 4 hours later. Two doses are needed because it wears off in a short time.1

Doctors do not understand how Xyrem works to treat cataplexy. It is believed that it helps with daytime sleepiness by improving the quality of nighttime sleep.2

What are the possible side effects of Xyrem?

Xyrem has many possible side effects. The most common side effects are:2-4

  • Morning sleepiness
  • Nausea, vomiting, diarrhea, stomach pain
  • Dizziness
  • Loss of bladder control (bedwetting)
  • Headache
  • Back pain
  • Weakness
  • Swelling of the arms, hands, feet, ankles, or lower legs
  • Sweating
  • Tremors

Serious side effects should be reported to a doctor right away and include:2-4

  • Confusion at night or while awake
  • Sleepwalking
  • Agitation, anxiety, depression, paranoia, aggression
  • Changes in weight or appetite
  • Suicidal thoughts
  • Hallucinations
  • Psychosis
  • Seizures
  • Weak or shallow breathing, breathing that stops
  • Coma

These are not all the possible side effects of Xyrem. Talk to your doctor about what to expect or if you experience any changes that concern you during treatment with Xyrem.

Things to know about Xyrem

Xyrem is also known as gamma hydroxybutyrate, or GHB. Because of its potential for abuse and misuse, the U.S. Food and Drug Administration (FDA) tightly controls its use, and it comes with serious warnings.

Xyrem may be habit-forming. This means cravings can develop. The person may want to take larger and larger doses, or take the drug despite unpleasant side effects. Stopping Xyrem suddenly may create withdrawal symptoms. It is better to gradually take less Xyrem over time, with the guidance of your doctor.4

Your doctor must be registered in a special program to be able to prescribe Xyrem. Then, you will only be able to get the drug from a certified pharmacy that is also part of the program. The program is called Risk Evaluation and Mitigation Strategies (REM) and is run by the FDA.

Before beginning treatment for narcolepsy, tell your doctor about any other drugs, vitamins, or supplements you are taking. This includes over-the-counter drugs.

For more information, read the full prescribing information of Xyrem.

Other treatments for narcolepsy

In addition to Xyrem, other drugs that are used to treat narcolepsy include stimulants and antidepressants. Your doctor will decide which treatments are best for you based on your individual symptoms and how you respond to different drugs.

People being treated for narcolepsy should see their doctor every 6 months. All of the drugs taken for narcolepsy can interact with many other medicines. It is important to watch for drug side effects, changes in sleep or mood, and other health issues.1

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